Posted on 12/07/2016 2:56:09 PM PST by BenLurkin
The latest findings in Earth science are brought to you by ancient astronomers who observed the heavens as much as 2,700 years ago.
Thanks to hundreds of records of lunar and solar eclipses carved in clay tablets and written into dynastic histories, modern scientists have determined that the amount of time it takes for Earth to complete a single rotation on its axis has slowed by 1.8 milliseconds per day over the course of a century, according to a report published Wednesday in Proceedings of the Royal Society A.
It may not sound significant, but over the course of 2½ millenniums, that time discrepancy adds up to about 7 hours.
In other words, if humanity had been measuring time with an atomic clock that started running back in 700 BC, today that clock would read 7 p.m. when the sun is directly overhead rather than noon.
“There is time and then there is how fast the Earth spins,” said Duncan Agnew, a geophysicist at Scripps Institution of Oceanography in San Diego, who was not involved with the work. “Traditionally those things are closely linked, but they are not the same.”
Our earliest ancestors measured time based on the position of celestial bodies in the sky, such as the rising and setting of the sun or the changing shape of the moon. Scientists refer to this as Universal Time, and it is governed by the dynamic gravitational motions of the Earth, moon and sun.
Terrestrial Time, on the other hand, is measured by clocks and is independent of planetary motiont. Since the 1960s, it has been tracked by exquisitely precise atomic clocks. According to our modern take on Terrestrial Time, there are exactly 86,400 seconds in a day and each second is defined as exactly 9,192,631,770 oscillations of a cesium-133 atom.
(Excerpt) Read more at latimes.com ...
Global lighting.
That would be some awesome wrist watch.
This article is junk science and fake news. If the earths rotation was truly slowing by that fast of a rate it would’ve already quit rotating billions of years ago. Once the earth is tidally locked with the moon and it only revolves roughly once a month then there will be no life on this planet.
Junk science, fake news, doomsday porn.
Regarding eclipses, the remarkable thing about the relationship of the Moon, Earth and the Sun is how perfectly the Moon eclipses the view of the Sun for people on Earth. It wasn’t so in the geological past, when the Moon was closer to the Earth, nor will it be so in the distant future, when the Moon will be farther away from Earth. Our maker created the heavens so they perfectly line up for human civilization to ponder and enjoy. Enjoy it while it lasts!
So this is 1.8 x 365 = 657 milliseconds per year. That is more than half of a second per year.
This has to be nonsense. It implies that the day was half an hour shorter 2700 years ago.
Junk science.
So my 24-hour parking pass at the Colosseum was a gyp!
No, not so. The numbers are correct. They added up the "lost" milliseconds over 2-1/2 millenniums to come up with a 7 hour total, which in itself means nothing. But the daily "lost" millisecond is correct. The Earth indeed is slowing its rotation, and the tidal lock with the Moon is slowly being altered as the Moon's orbit gradually extends outwards away from Earth. Life on this planet will do just fine for thousands, if not millions of years before major changes take place.
No it was 24 hours but the hours were shorter.
There is going to be a “leap second” this year, on December 31st. Be sure to reset your chronometers.
A loss of more than half a second per year is correct, and not nonsense. See this article which simply explains it.
http://www.physlink.com/Education/AskExperts/ae695.cfm
“Every 18 months on the average, with variation, a leap second is added to planetary time keeping to keep the day consistent with atomic clocks and astronomical observations.”
“The next leap second will be at the end of December 2005. The one before that was December 1998.”
Certainly in the last eight years, that’s for sure
There is no truth to the rumor that the government unions are wanting a pay adjustment for the time differences./s
Yep, a second will be added at New Year’s day. Will it play havoc with the dropping of the New Year’s Ball in New York?
Not junk science and possibly beginning to get at just how antideluvian people lived to be 600 years old.
Hmm...the Sun is orbiting the Earth just a little slower each year? Congress should pass a law speeding it back up. Why do I always have to be the smart guy who figures out these things?
All the gov’ment has to do is add another hour to DST. That should do it.
Global slowing can be stopped by more taxes.
"We can use extremely accurate atomic clocks to measure exactly how much the rotation is slowing down. One hundred years from now, a day will be about 2 milliseconds longer than today. Two milliseconds is 1/500th of a second, or how long it takes a car going 55 mph to travel only 2 inches—in other words, much less than the blink of an eye. So, if you live to be 100, you can't complain that the days are getting shorter! At this rate, though, you don't have to worry about the days getting enough longer to change things very much."
Source http://spaceplace.nasa.gov/review/dr-marc-earth/earth-rotation.html
With the earth's rotation slowing at only 1.8 ms per century that means 10,000 years ago the earth day with shorter by only 18 seconds.......
1.8 milliseconds per day is 657 milliseconds per year which comes out to about 1840 seconds in the last 2800 years. It’s been awhile since I got out of school, but isn’t that round a about a half hour? Must be that new math or something.
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